There was a time when much of the very best loudspeaker technology emanated from the UK – but sadly, for the most part, those days are over.

With the singular exception of B&W, most truly interesting and high-class loudspeaker design now comes from North America, the Far East and elsewhere in Europe. Of course, some companies design their products here and have them built over there – in the Far East, mainly – KEF being a prominent example.

Monitor Audio is also associated with Far Eastern manufacture, albeit for cost reasons. Since Mo Iqbal relinquished the company’s reins a decade or so ago, the brand has been principally involved with technologically conservative low- to mid-range loudspeakers, which might be described as ‘mainstream affordable’.

In the main we’re talking about loudspeakers that don’t sap amplifier resources unduly, and which are mostly reasonably compact and affordable, if sometimes a bit too sharply dressed to blend in with many domestic surroundings.

But here’s a new departure for Monitor Audio – an unashamedly luxurious, technically ambitious loudspeaker that’s the result of a ‘blue sky’ project, where decisions about materials and construction techniques have been made with a purist focus, and largely without regard to cost or technical difficulty. This marks the entry of the long-established brand into the high-end market.

The voice-matched Platinum range includes a smaller two-way derivative – which could be used either as a stereo speaker or as a rear speaker in a multichannel system – a centre-channel speaker that, technically speaking, is very closely related to the model tested here, plus the obligatory subwoofer, of course.

The aim for these models was to marry traditional British craftsmanship with what Monitor Audio describes as “benchmark” performance.

This would appear to refer to consistent sound across the range, with greater refinement and musical integrity than with previous efforts, as well as very low distortion and a considerably broader frequency coverage (>50kHz), appropriate to the bandwidths ushered in by media such as DVD-A, SACD, HD-DVD and Blu-ray.

Responsibility for this ambitious project was assumed by a recently expanded team of acoustical engineers and industrial designers, led by technical director Dean Hartley and based in Rayleigh in Essex.

Monitor Audio has also introduced in its own 3D modelling, finite-element simulation and a Klippel distortion-analysis system supported by an in-house anechoic chamber. This investment is clearly intended to pay further dividends with future projects.

The PL300 is an imposing loudspeaker, standing as it does at over 1.1 metres tall and set against broad shoulders and a deep cabinet.

The side panels are alternatively bowed inwards (at the back) and outwards (at the sides) for resonance-control purposes. It’s a three-way, four-driver design, with two identical 200mm bass drivers, a 100mm mid unit and – in a complete break with Monitor Audio practice, which has always previously favoured metal domes – a proprietary ribbon tweeter.

Bass loading is via two rear-facing, rifled HiVe II high-speed vents. Front baffles, plinths and the midrange housings are cast from an anti-resonance composite (ARC) material, a thermoset polymer that’s loaded with minerals to provide very inert, optimally damped assemblies.

The ARC material is cast to form a tapered line enclosure for the Platinum’s midrange driver. The main enclosure’s front and rear panels have additional reinforcement from long steel support struts that are tightened to a specific torque as an additional resonance-control method.

They’re barely needed, however; the internal construction of the PL300 and the build of the main chassis itself shows a great deal of attention has been paid to this major parameter.

The standard of fit and finish on the model is nothing less then exquisite, and this includes the quality of the adjustable spiked feet, the WBT Platinum Signature bi-wire terminals and the 11 layers of clear-gloss piano lacquer that highlight the wood grain.

To add a little extra touch of luxury to the package, along with some additional damping (though this isn’t its primary purpose), the baffle is upholstered in Strathspey leather, which is said to be superior to other leathers sometimes employed in similar applications. The woods used are Santos rosewood and natural ebony veneers.

The drive units clearly aren’t from the standard Monitor Audio parts bin. All driver surfaces employ ceramic-coated aluminium/magnesium (C-CAM). On the bass and midrange units, the cones consist of cores of Nomex honeycomb resins sandwiched between thin C-CAM layers, the concave cone profiles shaped with the aid of FEA analysis.

High frequencies are generated by a short and not excessively directional C-CAM alloy sandwich ribbon, with a neodymium rare-earth magnet.

The ribbon doubles as the voice coil, and weighs just 18mg (less than half the weight of a typical high-performance dome), which helps account for the impressive 100kHz tweeter frequency-response limit, key to the speaker’s ability to complement the new broad-bandwidth formats.

The ribbon is also very narrow, which means a wider then usual lateral dispersion, the limited height causing a more than usually curtailed vertical dispersion too.

This review was carried out shortly after moving to new premises, which of course meant a new listening room, with completely different acoustics to those this particular reviewer is accustomed to.

The room is tall, moderately wide and about 12 metres long, so there’s plenty of air to stir. We were told in advance that our review speakers were well travelled, having been used as demonstration models in other countries. In any event, we could detect no warm-up or running-in traumas that weren’t directly attributable to the other components in the system.

In fact, there were no traumas of any kind, which compares favourably with most of the high-end speakers we’ve used in the recent past – though we suspect the Focal-JMlab Utopia Be would have been an interesting match, as well as offering even greater low-frequency bandwidth and maximum volume capability.

Not that the PL300 is particularly limited in either department. The bass is well extended and very clean and agile.

It’s more than capable of sustaining fortissimo orchestral playing with real power and authority, and its speed and agility are even more impressive than its sheer depth, though having said that, a smaller room would probably have thrown the spotlight more firmly on the low-frequency ‘presence’ end of the spectrum.

But with the right music, performed properly, the PL300 can mount a musical picture of devastating authority and weight, without any noticeable overhang or excess.

However, it’s in two other areas that this speaker is most impressive. First, there’s the almost complete absence of coloration, and the model’s corresponding transparency. The only speakers that come close in this area are top-end electrostatics.

The sound possesses a sharpness, clarity and precision, but with absolutely no detectable overhang. This is certainly linked to the very subtle discrimination the PL300 provides to high-frequency musical content, and the airiness that’s often heard from top-class wide-bandwidth tweeters.

In many ways it’s suggestive of the performance of the Focal beryllium tweeter and the B&W diamond tweeter, which are certainly the best domes currently available.

The sounds of individual instruments are particularly well served, with a very subtle, tactile quality where the music demands it. For example, the individual strings on an acoustic guitar and glissandi from a harp – which, with poor reproduction quality, may be masked in orchestral recordings – are incredibly striking.

The effect is nothing short of breathtaking, providing some real spine-tingling moments, in a way that you often hear in a live music event, but rarely encounter in the reproduced article.

There’s similar quality with one of this month’s featured recordings, the Natalie Clein recording of Elgar’s Cello Concerto, which from the first note brings the solo instrument to life in a remarkable and thoroughly tactile way. The electrostatic-like quality of this speaker, despite having no electrostatic transducer built in, was noted explicitly by a number of visitors.

The second area where the PL300 truly excels – even outshining other speakers with ribbon tweeters – is its dispersion. The tweeter has a broad lateral radiation pattern, which makes it more usable than expected – even well off the tweeter’s main firing axis.

There’s some roll-off when listening from either side, as the PL300 can’t repeal the laws of physics, but the change in voicing is remarkably modest with changes in incident angle, and there certainly isn’t the marked ‘hot seat’ effect characteristic of ultra-wide-bandwidth domes.

Unsurprisingly, there’s more variation on the vertical axis, although it’s not excessive, so that standing up and moving around the listening room while listening casually at least, doesn’t result in any disproportionate change in voicing.

There is a positive side effect here, which is that floor and ceiling reflections are effectively damped down. We noticed that a point in the room that tends to sound rather bright, apparently associated with a projecting RSJ strut running across the room, was less affected than usual using this Monitor Audio speaker.

Earlier on, we described the Platinum series as unashamedly luxurious, with the clear implication that they’re also unashamedly expensive. Well, they’re not cheap, but £5K for a pair of speakers of this complexity, build quality and, above all, musical performance is far from extravagant.

The overall musical effect is very expressive, airy and natural, with a clearly well-extended response, especially in the high treble.

Thomas J. Norton  |  

 

Performance
Build Quality
Value

Price: $26,000 (excluding stands, updated 3/11/15)
At A Glance: Pristine highs, uncolored mids, tight bass • Great dynamic range • Subwoofer lacks wallop in the deepest, loudest bassBetter Than Golden

Founded in 1972, U.K.-based Monitor Audio has long produced speakers that offer good value. Until recently, it topped out at $4,500 per pair for the Gold Signature model. So when I heard about the new Platinum range, priced at $10,000 per pair for just the front left and right flagship PL300, it came as a surprise. (Editor’s note: See updated pricing on Features & Specs page)

The Platinum range is manufactured in China but engineered and designed in the U.K. Although it isn’t exactly priced for supermarket coupon clippers (particularly when you purchase them as a complete home theater package), it is clearly a design, engineering, and sonic tour de force.

Light and Rigid
The woofer and midrange cones in all of the Platinum models start with a core of honeycombed Nomex material in a shape that’s refined by Finite Element Analysis (FEA). Using a process developed by Monitor Audio—called Rigid Diaphragm Technology (RDT)—this core is layered with an ultra-thin skin of C-CAM. This material is half the thickness of a human hair, and it consists of an aluminum-magnesium alloy with a ceramic coating.

The resulting structure is said to be about 150 times more rigid than a single-layer C-CAM cone and a fraction of the weight. It is seamlessly concave, it eliminates the need for a dust cap, and it’s combined with a voice coil and magnet system designed for very low distortion. The 8-inch woofers employ long-throw voice coils, and their cones are stabilized by dual spiders.

However, the biggest leap here is Monitor Audio’s departure from the dome tweeters it’s used in all of its other past and present models. Instead, Monitor has designed a new ribbon tweeter specifically for use in the Platinum line. It’s a pure ribbon configuration with a thin diaphragm of C-CAM alloy that has a mass of 18 milligrams. Its suspended in a magnetic field produced by rare-earth magnets. Its specified upper response is 100 kilohertz—not that our tests can verify this!

The Platinum cabinets’ front baffles, bases, and tapered internal midrange housings are fabricated from ARC, a thermoset, mineral-loaded polymer that’s said to be inert and highly damped. Cabinet vibrations are additionally suppressed by a combination of internal bracing, bituminous material, and steel bolts that tie the front and back panels to the internal braces. The PL300’s crossover is encased in the ARC base for better isolation from cabinet vibrations.

Monitor’s commitment to quality is also visible in the Platinum line’s finishing touches. The laminated side and back panels are gently curved, and the cabinets are finished with 11 layers of clear gloss polyester. The front baffles are upholstered in Strathspey leather (except for the PLW-15 subwoofer). I’m no authority on leather, but that sounds impressive, and it certainly looks and feels like it came from a high-end cow.

The backs of the full-range Platinum models are fitted with two pairs of biwireable, platinum-coated input terminals. Monitor provides heavy-duty adjustable spikes, and you can fit them to the PL300’s base (and the optional stands for the PLC350 center and PL100—the latter used here as surrounds). You can remove the spikes from the feet, which also have rubberized inserts for use on wood or tile floors. The speakers have removable grilles, which are held in place by invisible, imbedded magnets.

The PLW-15 subwoofer’s 15-inch RDT C-CAM driver, with its 4-inch voice coil, is triple-suspended in a die-cast chassis and driven by a 1,000-watt Class D amplifier. It offers a wide range of adjustments, including a 10-band, one-third-octave graphic equalizer (at 20, 25, 31, 40, 50, 63, 80, 100, 125, and 160 hertz, with +/–6-decibel adjustability in 0.5-dB steps). The sub also has a remote control, but you have to hear, and not see, what it’s doing from your seating position. The small indicator window that provides feedback on your adjustments is on the top of the cabinet, so you can only see it if you’re standing over the sub. Even if it were mounted on the front, the window is too small to read from across the room.

Setup
I set up the Platinum system in my 26-by-15.5-by-8-foot home theater space. I positioned the PL300s to the left and right of my projection screen, which was well away from any nearby walls (and retracted when the listening was music only). The speakers were roughly 9 feet apart and toed in toward the main listening seat. I removed the grilles and didn’t use the spikes (to avoid marring the vintage oak flooring under my room’s large area rug). I didn’t use biwiring. I used a Parasound Halo A 51 power amp and an Integra DTC-9.8 surround processor to drive the speakers. Sources included a Pioneer Elite DV-79AVi DVD player and a Panasonic DMP-BD35 Blu-ray player.

All of the main-channel bass below 80 Hz (including that from the floorstanding main speakers) was directed to the subwoofer via the crossover in my surround processor. The bottom end of the PL300s was rolled off below 80 Hz whenever the subwoofer was engaged (as it was for most of my listening, unless otherwise noted). However, I drove the PL300s full range when I auditioned them without a sub. I set up the sub’s graphic equalizer to produce optimum response at the main listening seat.

Making Music and Movies Real
I began my listening with two-channel music using the PL300s and the PLW-15 subwoofer. The first thing I didn’t notice was the highs. Ironically, that’s what makes Monitor Audio’s new tweeter special. You don’t hear the high frequencies from its ribbon tweeter so much as sense them as an integral part of the overall sound.

Yes, the PL300s are sweet sounding, but sweet can be a euphemism for soft, which these speakers definitely are not. They’re incisive without being fierce or biting. The amount of detail they brought to the party constantly amazed me. The gorgeous percussive detail on Mokave’s Afrique (AudioQuest) was immediate yet relaxed. Transients started and stopped on a dime, but they never overshot the mark into zing or raspiness. Strings were silky smooth.

The PL300s also threw an impressively wide soundstage. Their outstanding imaging was no surprise. In my room, most good speakers image exceptionally well, which is undoubtedly helped by being 2 feet or more away from any walls. Nevertheless, the center image was so tight on two-channel material that you’d swear the center speaker was playing, even when it wasn’t. The sonic balance was a little more forward than I’m accustomed to, but the PL300s still produced a fine sense of depth.

I did notice an occasional touch of glare that originated, I would guess, in the upper midrange. But guesses are for financial advisers, so we’ll have to see if it shows up in our measurements. (See HT Labs Measures, next page.) This anomaly didn’t raise its head often, although loud brass and complex, loud passages featuring a full symphony orchestra were more prone to it than pop, jazz, and most vocals. The latter music categories often sounded stunningly natural.

I never experienced this issue when the system was fired up in full multichannel mode. The Platinums handled the most challenging soundtracks, from explosive sound effects to full-bodied symphonic orchestral scores. And they did it without breaking a sweat, even at silly-loud playback levels.

To sub or not to sub? During the music listening, I found the PL300s to be surprisingly extended in the deep bass even without a subwoofer. Most music listeners will be delighted with their extended low-frequency performance. If your taste in movies runs toward lighter, Armageddon-free fare, the PL300s alone just might satisfy all of your home theater bass needs. Still, a good separate subwoofer will go deeper, especially if you’re passionate about organ or synthesizer music. And it can better handle truly subterranean, high-level bass (a vital complement to action movie soundtracks).

What about movies? Outstanding. My taste in demo material often includes animated fare, not only because I love the medium, but also because animation producers have given us some great-looking and great-sounding discs. Final Fantasy: The Spirits Within is one of the best (and most underappreciated) soundtracks out there, particularly the uncompressed version on Blu-ray. It covers all the bases from the subtle to the explosive, with a soundstage as small or immense as it needs to be. The bass digs deep, and the highs are as detailed as you could want. The Platinum speakers do it all here, with full-bodied, extended bass without bloat, a natural midrange, and crisp, precise highs without edginess.

Another great but also little heralded animation soundtrack is Chicken Little (Blu-ray). While its uncompressed soundtrack doesn’t have the bass extension of Final Fantasy, it’s loaded with other treats. In particular, the interior of the alien spaceship (yes, I’m talking about Chicken Little here) is richly layered with subtle sonic detail, intermittently interrupted by explosive transients. The score is also beautifully recorded, particularly with Five for Fighting’s cover of the song “All I Know.” It was all great fare for the Platinums, and they didn’t let me down.

Experiencing The Dark Knight (Blu-ray) on the Platinums was awesome. Even when I played it louder than I felt comfortable with, the Platinum system’s ease and lack of strain during the soundtrack’s greatest challenges blew me away. I was never tempted to turn down the volume when the going really got going. The deepest bass was satisfyingly extended and tight but just a little short of gut-wrenching (more on this below). I performed this particular audition late at night, and the action got so intense that I was a bit concerned the neighbors might call the cops to report gunshots coming from my house! Fortunately, they didn’t.

The PLC350 center channel and PL100s also held up their ends of the bargain. (The PL100 is a full-range monitor that’s entirely suitable for main-channel duties, although you will need a subwoofer for any serious low-end grunt.) While the center is a good spectral match for the PL300s, it sounded a little forward when I listened to it directly on axis. It was better balanced when I moved a few degrees to the left or right. Fortunately, I sit a little off center for movie watching, so this characteristic didn’t bother me.

I found the Platinums less than stellar in only one respect. The PLW-15 subwoofer is without question a good one. It has excellent extension, tight response, and many useful controls. But considering its price, there may be better and somewhat more affordable options. And I just happened to have one on hand: the Revel Performa B15a sub. I alternately positioned both of these subs in the best location in my room. Both subs offer equalization (graphic equalization in the Monitor Audio, three-band parametric in the Revel), and I used this to match the two as closely as possible.

With some material, the Monitor Audio sub sounded tighter. But while it appeared to go almost as deep as the Revel with subtle, low-level bass, it did not do so when the bass turned loud and energetic. The Revel showed occasional signs of strain on the most challenging material. The Monitor Audio did not. But that didn’t stop the Performa B15a from producing a much more ominous sense of foreboding in Spielberg’s War of the Worlds (DVD) as the first alien tripod rumbles up out of a Brooklyn street. It also produced a more suitably aggressively bottom end on The Dark Knight. The differences on music were usually subtler, but when they were not, the Revel sub still came out on top.

Conclusions
It’s been more than a year since I parted ways with the Revel Ultima Studio2, but that system still stands out as the best speaker package I’ve had in my current listening room. Time blurs the details, but the Revel’s highs were a bit airier than the Monitor Audio’s, although they were also a bit more obvious. Midrange coloration was comparable, but the Revels were slightly more laid back. The Revel’s Ultima2 Voice2 center was also a bit more neutral on axis and varied less at far off-axis angles. As an overall package, the Monitor Audio is barely a step below the Revels, yet it costs $13,000 less.

Twenty-five big ones is a lot of money for loudspeakers, especially in a market where there are excellent and far less expensive alternatives. But the sort of engineering, sound, and aesthetic refinements in the Monitor Audio Platinums rarely come cheap.

I’d never recommend that anyone buy speakers sound unheard. But I do recommend a serious audition of the Platinums if you’re shopping for the best. Unlike some surround systems, I can say that if you’re only able to audition the PL300s alone in a two-channel setup and like what you hear as much as I did, you’ll be in heaven with the full surround package.